Firepower is a great game. No doubt about that.
That era of WMS machines were not too bad as far as reliability goes, but the issues with the interconnect pins for CPU / Driver board will never be 100% reliable.
I don't know whether the video is of the actual machine, as it appears to have the correct backglass.
Big headaches with shipping a backglass from the US and not cheap.
My concerns that why would you not finish stenciling the cab, repairing the targets properly etc???